drm/i915: Check if the size is too big while creating shmem file

The __shmem_file_setup() function returns -EINVAL if size is greater than
MAX_LFS_FILESIZE. To handle the same error as other code that returns
-E2BIG when the size is too large, it add a code that returns -E2BIG when
the size is larger than the size that can be handled.

v4: If BITS_PER_LONG is 32, size > MAX_LFS_FILESIZE is always false, so it
    checks only when BITS_PER_LONG is 64.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221228192252.917299-5-gwan-gyeong.mun@intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index 28e857f8c16922cf256e2aac3c581dff467b15a3..e767791e40e0a00e43403f7bc5a1b825e362be5d 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -541,6 +541,20 @@ static int __create_shmem(struct drm_i915_private *i915,
 
        drm_gem_private_object_init(&i915->drm, obj, size);
 
+       /* XXX: The __shmem_file_setup() function returns -EINVAL if size is
+        * greater than MAX_LFS_FILESIZE.
+        * To handle the same error as other code that returns -E2BIG when
+        * the size is too large, we add a code that returns -E2BIG when the
+        * size is larger than the size that can be handled.
+        * If BITS_PER_LONG is 32, size > MAX_LFS_FILESIZE is always false,
+        * so we only needs to check when BITS_PER_LONG is 64.
+        * If BITS_PER_LONG is 32, E2BIG checks are processed when
+        * i915_gem_object_size_2big() is called before init_object() callback
+        * is called.
+        */
+       if (BITS_PER_LONG == 64 && size > MAX_LFS_FILESIZE)
+               return -E2BIG;
+
        if (i915->mm.gemfs)
                filp = shmem_file_setup_with_mnt(i915->mm.gemfs, "i915", size,
                                                 flags);